Sumatran tigers are found only on the Indonesian islands of Sumatra. They are the smallest of all tigers and also have the narrowest stripes.

Tim Rowlands, curator of mammals at Chester Zoo, said: 'Sumatran tigers are one of the rarest big cat species in the world.

'That's what makes our new tiger trio so incredibly special - they're a rare boost to an animal that's critically endangered.

'It's still early days but Kirana is an experienced mum and she's keeping her cubs very well protected. She's doing everything we would hope at this stage.'

Mr Rowlands added: 'The arrival of this latest trio of cubs is vital to the ongoing survival of the species and the back-up population found in zoos. They are now part of a safety-net against the population in the wild becoming extinct which, to me, is incredibly humbling.'

The gender of the cubs, born on 2nd January, is still unknown and it will be several weeks until zookeepers discover the sex of the tiger triplets and give them their names.

Scroll down for video

Three of the world's littlest big cats have taken their first steps into the spotlight at a UK zoo. The three-week-old Sumatran cubs cautiously emerged from their den at Chester Zoo, under the watchful eye of their mother Kirana

Peering into the sunlight, these tiny tiger triplets take their first steps into the real world. Sumatran tigers are found only on the Indonesian islands of Sumatra. They are the smallest of all tigers and also have the narrowest stripes

The chubby cubs are so little that keepers do not expect to learn their sexes for several weeks. But it's hoped the as-yet nameless triplets will help ensure a future for their species

The inquisitive babies peered cautiously out from their den before bounding out into the world. The species has been forced to the brink of disappearance by deforestation and poachers

One of the cubs takes the lead and ventures out into the sunlight, cautiously followed by a shy sibling. The tigers are poached for traditional medicines and much of their jungle habitat has been destroyed

One of the baby tigers seemed keen to practice his best growl as he snarled at waiting photographers

The cub's doting parents, eight-year-old mother Kirana and seven-year-old father Fabi, proudly accompanied the little ones, much to the delight of staff at the zoo

Staff at the zoo said Kirana is an experienced mother and she's keeping her cubs very well protected. Mammals curator Tim Rowlands said: 'She's doing everything we would hope at this stage'

Tim Rowlands, curator of mammals at Chester Zoo, said: 'Sumatran tigers are one of the rarest big cat species in the world. That's what makes our new tiger trio so incredibly special - they're a rare boost to an animal that's critically endangered'

Eight-year-old tigress Kirana with one of her three as yet unnamed Sumartran tiger cubs. The tigers were born on January 2, in their enclosure at Chester Zoo. It is the third time Sumatran tiger cubs have been born at the attraction with Kirana producing litters in October 2011 and in June 2013